Metal envelope electric discharge device



Feb. 28, 1950 w, PosEY 2,499,197

METAL ENVELOPE ELECTRIC DISCHARGE DEVICE Filed NOV. 24, 1948 Fg/ W /3Fig. 5.

Inventor: William T Pese a,

Patented Feb. 28, i956 METAL'ENVELOPE EL Eo'raio DISCHARGE DEVICEWilliam T. Pusey, Schenectady, N. Y. assignor to General ElectricCompany, a corporation of New York Application November 24, 1948, SerialNo. 61,774

' 2 Claims. (01. 250-215) My invention relates to metal envelopeelectric discharge devices of the type employing an ionizable mediumand, particularly, to an improved construction for facilitating thecharging of such devices with a predetermined quantity of ionizablemedium.

It has been customary to introduce an ionizable medium, such as mercuryor a gas or a combination of the two, into discharge devices having aglass envelope by placing an ampule containing the medium within theenvelope in such a position that it may be shattered by high frequencyinduction at a desired time in the processing of the device. It is notpossible to do this for metal envelope discharge devices due to thecomplete shielding action of the metal envelope. Automatic injectionapparatus has been provided on exhaust machines for supplying theionizable medium to discharge devices of this type and, while thismethod has in general been satisfactory, it materially increases thecost of manufacture and the complication of the exhaust machines. Inaccordance with an important aspect of my invention, I provide a novelconstruction which permits charging of metal envelope devices with apredetermined quantity of ionizable medium by shattering an ampulecontaining the medium by mechanical deformation of a part of theenvelope.

The objects and advantages that characterize my invention will becomemore apparent as the following description proceeds, reference being hadto the accompanying drawing in which Fig. l is an elevational View,partially in section, of a metal envelope device embodying my invention;Fig. 2 is an enlarged perspective view of a supporting structure for theampule as employed in the device of Fig. 1; Fig. 3 is an enlargedelevational view, in section, of the tubulation of the device of Fig. 1prior to sealing off; and Fig. 4 is a similar enlarged elevational viewafter sealing off and after the ampule has been shattered by deformationof the tubulation.

Referring now to the drawing, I have shown my invention as employed in ametal envelope type discharge device including a generally cylindricalmetal envelope l which is closed at its lower end by an invertedcup-shaped metal header 2 which is bonded, as by welding, to the lowerend of the envelope I. An elongated metal tubulation 3 communicates withthe interior of the envelope I through the header 2 and is joined to theheader by an outwardly extending flange 4 which is preferably welded tothe inner surface of the header. The tubulation is provided at its lowerextremity with a portion 5 of reduced cross section which, in thecomplete tube, is welded together at its lower end, as indicated at 6.As shown in Fig. 3, a glass ampule 1 containing a quantity of mercury 8and, if desired, also a quantity of gas 9 is housed by and supportedwithin the tubulation by a pair of opposed hollow metal members I0 whichare joined together in longitudinally offset relationship to provideopenings II and I2 through which the ionizable medium may readily escapeupon shattering of the ampule 1. The support and enclosure thus formedare supported in that portion of the tubulation extending below the tubeenvelope I by a wire I 3 which is bonded to one of the members Ill andto the flange 4 of the tubulation.

The tubulation is in the form shown in Fig. 3 while exhaust of thedevice takes place. After exhaust is complete, the lower end of thetubulation is sealed off, as shown at 6 in Figs. 1 and 4. Subsequently,the tubulation is deformed by suitable dies It in the region of theampule 1 to reduce the cross section of the tubulation sufficiently toshatter the ampule and release the ionizable medium. The openings II andii! are sufliciently small to retain most of the glass within the casingformed by the metal parts In.

In the interest of simplifying the drawing, the electrodes of the devicehave not been illustrated. It will be appreciated that when theinvention is applied to a thyratron having a metal envelope that ananode, a control grid and a thermionic cathode will be supported withinthe envelope in mutually insulated relation.

It will be apparent from the foregoing description that the presentinvention provides a very simple structure making it possible tointroduce the ionizable medium within metal envelope devices by means ofan ampule and that the shattering of the ampule by a mechanicaldeformation of the tubulation is easily and positively accomplished.

While I have shown and described my invention by reference to aparticular embodiment thereof, it will of course be understood that I donot wish to be limited thereto since various modifications may be made,and I contemplate by the appended claims to cover any such modificationsas fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric discharge device of the type utilizing an ionizablemedium comprising a metal envelope, a metal tubulation extending fromsaid envelope, a frangible ampule containing a quan-.

envelope; a perforatedldeformable support'in-said tubulation, afrangible ampule containing a quantity of ionizable medium within saidsupport so 10 that said ampule may be shattered andsaid medium liberatedby deformationofsa'id' tubulat'iom 3. An electric discharge device ofthe type utilizing an ionizable medium: comprising: almetalz envelopeclosed at one end by a: headerya' metal tubulation extending from saidheader and beyond the sidewall of said envelope, adeformable: supportpositioned in said tubulation and having,

an opening therein, a frangible ampule contain' ing a quantity ofionizable medium positioned within said support so that said ampule maybe shattered and said medium liberated through said opening bydeformation of said tubulation and said support.

' T; POSEY.

REFERENCES CITED The following references are of record in the fileofthis patent:

UNITED STATES PATENTS Number Name Date 1,23-I,4I6 Needham June 26, 19171,841,034 Ives- Jan. 12, 1932 2,091,915" Elder. ..1 Aug. 31, 19372,150,770 Kingdon Mar. 14, 1949

